A conventional dispensing system for supplying heated adhesive (i.e., a hot-melt adhesive dispensing system) generally includes a melter configured to receive adhesive in solid or semi-solid form and then heat and/or melt the adhesive, a pump in communication with the melter for driving and controlling the dispensation of the heated adhesive out of the melter, and one or more adhesive dispensing devices (e.g., guns or modules) receiving the heated adhesive from the pump. One or more hoses or manifolds may also be included in the dispensing system to direct the heated adhesive between the melter, pump, and dispensing devices. One particular type of melter used with conventional dispensing systems is a tank melter which includes a relatively large tank for storing molten adhesive that is to be delivered as needed by the dispensing devices. The tank is generally enclosed during normal operation to avoid releasing adhesive vapors formed during the melting of the adhesive into the surrounding environment. To this end, several types of adhesives used in dispensing operations require a positive seal on the tank during operation because the associated vapors can be hazardous.
However, the tank must also provide easy access for refilling or cleaning operations as well. As a result, an opening is provided on the top of the tank with a lid that can move between open and closed positions relative to the opening. The conventional lid is connected to the tank by a hinge adjacent to the opening. The lid rotates at the hinge between a generally horizontal orientation in which the lid covers the opening and a generally vertical orientation in which the opening provides access into the tank. In the closed position, the lid is held in position to seal closed the opening of the tank by the weight of the lid. Thus, the conventional hinged lid provides rapid and easy access into the tank when necessary while also enclosing the tank during normal operation.
Although the conventional hinged lid works well for its intended purpose of opening and closing the tank, this lid is subject to several drawbacks. For example, the tank in larger melters may have an opening that is located 48 inches or more from a ground surface. As a result, a handle on the lid may not be able to be held by all operators throughout the full range of the pivoting movement of the lid. In such circumstances, the operator may be forced to throw open the lid or tip the lid closed with a tool, and these actions often lead to uncontrolled movements of the lid between the open and closed positions. These uncontrolled movements cause the lid to stress the hinge, especially upon impact at the limiting open and closed positions. The stressing of the hinge may lead to damage of the hinge that renders the lid unsafe or inoperable. Moreover, the uncontrolled falling of the lid can pinch the hands or fingers of an operator at the opening. When the lid is opened, any adhesive droplets that condense on the lid from the vapors within the tank may fall down the generally vertical lid into the hinge. These droplets can solidify and adversely affect the operation of the hinge and the lid over time.
For reasons such as these, an improved lid assembly for use with a tank melter of an adhesive dispensing system would be desirable.